I get it and it does make sense. Humans always consider the unfamiliar dangerous by default, but I believe it's deeper and simpler than the arguments you present.
This is not a strictly human trait. Anthropologists are pretty sure we received this trait from our primate ancestors. It evolved out of family groups/tribalism.
Also, a large part of our brains are safety mechanisms. Many features are directed at keeping us alive which is why so many of our what if scenarios are about the worst happening.
In very tribal environments anyone not in your in-group is considered unsafe even if they look exactly like you (i.e. a tribe from 10 km away).
But the thing that has made humans the most successful species on Earth is our ability to override this behavior to cooperate at larger and larger scales.
This is not a strictly human trait. Anthropologists are pretty sure we received this trait from our primate ancestors. It evolved out of family groups/tribalism.
Also, a large part of our brains are safety mechanisms. Many features are directed at keeping us alive which is why so many of our what if scenarios are about the worst happening.
In very tribal environments anyone not in your in-group is considered unsafe even if they look exactly like you (i.e. a tribe from 10 km away).
But the thing that has made humans the most successful species on Earth is our ability to override this behavior to cooperate at larger and larger scales.